The known state of the art has battery management systems that connect a high-voltage battery to a consumer network via two contactors. Depending on the switching status of the contactor activator, either the high-voltage battery is connected to the consumer network or both poles are disconnected from the consumer network.
This function is for the sake of safety, to de-energize the consumer network downstream of the battery in the event of a fault. Thus the ability of the contactors to function properly is relevant to safety and must be monitored. Therefore it is necessary to check whether the contactor contacts actually close after the request for an electrical connection, and whether they actually open after the request for a disconnection.
A disadvantage of the state of the art is that components with considerable space requirements are needed to check the contactor contacts. Checking the contactor contacts necessitates voltage measurements, which are done across voltage dividers due to the high voltages. Accordingly, the voltage dividers must be laid out over a large area due to the required insulation spacing.